Exegesis:

paretērounto de auton … ei en tō sabbatō therapeuei ‘and (they) watched him (to see) whether he would heal on the sabbath.’ The present tense of therapeui has reference to habitual practice.

paratēreō ‘to watch closely,’ here with following indirect question.

ei ‘(to see) whether.’

hina heurōsin katēgorein autou ‘in order that they might find a reason to bring a charge against him.’ heuriskō with following infinitive, ‘to get a chance,’ ‘to find a reason’ (cf. L-Sc, s.v. heuriskō II.2).

katēgoreō ‘to accuse,’ ‘to bring charges against (somebody),’ with following genitive of the person; legal term.

Translation:

To simplify the structure of this sentence one may say, ‘some scribes … wanted to find an accusation against him. So they watched him to see if he would heal…’ (cf. Good News Translation), or, ‘watched him, asking themselves, “Will he heal…?” ’

Watched him, i.e. Jesus, not the man of v. 6. To watch, or, ‘to look-carefully-at’ (Toraja-Sa’dan, using an intensive form of ‘to see’), ‘to fix-with-the-eyes’ (Tae,’ using a derivation of ‘eye’); or, better to bring out the pejorative meaning, ‘to spy-on’ (Bahasa Indonesia, similarly Sranan Tongo).

If to heal requires an object (cf. on 5.17), it should be indefinite, “anyone” (Good News Translation), “people” (An American Translation, similarly most Indonesian languages), ‘the sick’ (Batak Toba), not definite and referring to the man of v. 6 (as is the case in Mk. 3.2).

So that they might find an accusation against him, indicates the result their action aimed at; hence, ‘their aim/intent/wish was to….’ Find an accusation against him, or ‘get a chance to accuse him.’ Some of the expressions used to render this phrase are, ‘find something which they will accuse him of (lit. make-sinner-about him)’ (Pohnpeian), ‘be obtained what they might cause to be his sin’ (Tzeltal), ‘find (opportunity) to place blame on him’ (Marathi).

Quoted with permission from Reiling, J. and Swellengrebel, J.L. A Handbook on the Gospel of Luke. (UBS Handbook Series). New York: UBS, 1971. For this and other handbooks for translators see here . Make sure to also consult the Handbook on the Gospel of Mark for parallel or similar verses.